A trucker hauling compressed gas cylinders finds himself in a new town. As he enters a very congested section of road, he notices the bridge ahead looks rather low. The sign reads 14'2". He knows that his truck is just over that height, so he has to stop just short of the bridge. Because of all of the traffic, he can't back up. What should he do?

Can he increase the space under the bridge? Yesish, he can do something that gives him the space that he needs, but the actual space under the bridge stays the same. eg by removing something from the bridge? No

Does it involve somehow raising the height of the bridge from the roadway? How about he fact that in the USA the engineers actually leave a little leeway between the actual height of the bridge vs. the marked height? Is the bridge adjustable in some fashion?

Is the bridge rigid? Yes Is it relevant what form of transport (if any) uses the bridge (including walking/bicycles etc.)? No Is the bridge permanent? Yes

Does it involve somehow raising the height of the bridge from the roadway? No How about the fact that in the USA the engineers actually leave a little leeway between the actual height of the bridge vs. the marked height? Good thinking, but no, the truck will not fit under the bridge where it's currently at. Is the bridge adjustable in some fashion? No, quite rigid.